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| author | Igor Lubashev <ilubashe@akamai.com> | 2019-08-27 03:39:15 +0200 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2019-08-28 22:19:19 +0200 |
| commit | 8859aedefefe7eeea5e67968b7fe39c828d589a0 (patch) | |
| tree | e7af29f67f95ff7b9c7dbb71c8007d271beca0b4 /tools/perf/util/symbol.c | |
| parent | perf evsel: Kernel profiling is disallowed only when perf_event_paranoid > 1 (diff) | |
| download | linux-8859aedefefe7eeea5e67968b7fe39c828d589a0.tar.xz linux-8859aedefefe7eeea5e67968b7fe39c828d589a0.zip | |
perf symbols: Use CAP_SYSLOG with kptr_restrict checks
The kernel is using CAP_SYSLOG capability instead of uid==0 and euid==0
when checking kptr_restrict. Make perf do the same.
Also, the kernel is a more restrictive than "no restrictions" in case of
kptr_restrict==0, so add the same logic to perf.
Signed-off-by: Igor Lubashev <ilubashe@akamai.com>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1566869956-7154-5-git-send-email-ilubashe@akamai.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to '')
| -rw-r--r-- | tools/perf/util/symbol.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 4efde7879474..035f2e75728c 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -4,6 +4,7 @@ #include <stdlib.h> #include <stdio.h> #include <string.h> +#include <linux/capability.h> #include <linux/kernel.h> #include <linux/mman.h> #include <linux/time64.h> @@ -15,8 +16,10 @@ #include <inttypes.h> #include "annotate.h" #include "build-id.h" +#include "cap.h" #include "util.h" #include "debug.h" +#include "event.h" #include "machine.h" #include "map.h" #include "symbol.h" @@ -2195,13 +2198,19 @@ static bool symbol__read_kptr_restrict(void) char line[8]; if (fgets(line, sizeof(line), fp) != NULL) - value = ((geteuid() != 0) || (getuid() != 0)) ? - (atoi(line) != 0) : - (atoi(line) == 2); + value = perf_cap__capable(CAP_SYSLOG) ? + (atoi(line) >= 2) : + (atoi(line) != 0); fclose(fp); } + /* Per kernel/kallsyms.c: + * we also restrict when perf_event_paranoid > 1 w/o CAP_SYSLOG + */ + if (perf_event_paranoid() > 1 && !perf_cap__capable(CAP_SYSLOG)) + value = true; + return value; } |